Yielding joint for extension rules



March 7, 1933. H. M. GASSTROM 1,900,640

7 YIELDING JOINT FOR EXTENSION RULES Filed April 5, 1929 I /a I? 1 Mli|1|| illlll MU WPHIHIMIIUJHUJMJ 6% c2 L142 35L, 75? ml avwowcoz Herman/7. fiassfrom Patented Mar. 7, 1933 UNITED STATES PATENT OFFICE:

HERMAN M. GASSTROM, F MOUNT VERNON, NEW YORK YIELDING J OINT FOR EXTENSION RULES Application filed April 3, 1929. Serial No. 352,186.

This invention relates to joints for foldable measuring rules, and it appertains particularly to such yieldable connections wherein the fiexure takes place in the direction of their pivots.

One object of the invention is to provide a joint of the class described, eliminating the stresses imposed directly on the members composing the rule, while the interrelative positions thereof are being changed. 7 Another object is to produce a joint of the character referred vto, having resilient elements coacting with the pivotal connection intermediate the hinged members of the rule to maintain the necessary tension therebetween.

A further object is the provision in a oint of the nature set forth, of means for applying the required pressure upon the overlapping ends of the rule members in close adjacency to their edges instead of at the middle thereof.

Still another object is the production of a joint of the type mentioned, in which the pressureelements for the ends of the wooden 1 strips composing the rule members, tend to hold them from splitting.

A still further object consists in providing a joint of the kind specified wherein frictional engagement only occurs intermediately the metal contacting surfaces of the pressure exerting elements and the pivotal con nections for the rule members, thus avoiding rubbing action between the latter and the aforesaid connections. V

An important object is to supply a joint of the species alluded to, having pressure applying elements disposed at the outer faces of each pair of rule members and so arranged as to protect the graduations and figures on adjacent members from wear.

A general object is to furnish a joint for the purpose in view which shall be of simple, strong and compact construction; capale of being embodied with existingtypes of rules; that will increase the durability of the connections between the rule members; and amenable besides, to low cost of manufacture and assembling. V e

Other objects and advantages of the invention willbecome apparent asthe specifica- 7 tion proceeds. 7 1 I lVith the aforesaid" objects in view, the invention consists of the novel combinations and arrangements of parts hereinafter described in their preferred embodiments,

pointed out in the subjoined claims and illustrated on the annexed drawing, wherein like parts are designated by the same reference characters throughout the several views. '6

Generally described, the invention under consideration includes in combination with the overlapping ends of adjacent members 7 of a folding or extension rule having interengaging joint plates, and the pintle which 5 passes thru both thereof. The headed over terminals of this pintle are received within centrally depressed portions of resilient, yoke-like elements that are made to overlie the opposed outer faces of the rule members 9 in a direction widthwise thereto. The eX- tremities of the aforesaid elements are provided with bent over anchorages adapted to take over and, if desired enter into the material whereof the members are composed. Such anchorages not only prevent displace ment of theelements relatively to thermombers referred to, but serve also to hold the latter, when madeof wood, from splitting; At such times as the rule'members are shifted one with respect to the other, i. e. swung from open to closed position or vie-e versa, when the interlocking cam-portions on their joint plates are move-d out of registry, themembers ofthe rule are also spread apart; The stresses thus produced are taken up -orresisted by the slightly arched yoke-elements, the yielding actions whereof permit thesemembers to pass over one another without] any appreciable strain being imposed thereon; Thebefore mentioned elements 'asiwell, perform the function of retaining the rule members aligned, whether open or closed. The outer faces of the yoke elements project beyond those of themembers of the rule, and in contacting with similar elements on adjacent' oppositely disposed members, when; the rule is folded, protect their graduations and figures from coming together. f r I The advantages of the. invention as here outlined are best realized when all of its features and instrumentalities are combined in the one and the same structure, but, useful devices may be produced embodying less than the whole. 7

It will be obvious to those skilled in the art to which the invention appertains, upon becoming conversant with the details thereof, that the same may be incorporated in several different constructions. The accompanying drawing, therefore, is submitted merely as showing the preferred exemplificat-ion of the invention.

In the annexed drawing which illustrates the invention in about twice natural size- Figure I is a fragmentary top plan view of a pair of overlapping rule members, showinga'yieldable retaining element in position thereon,

i Fig; II is a View similar to the preceding, but omitting the element referred to;

A Fig. III is a horizontal section taken longitudinally thru thecentre of Fig. I, looking upwardly thereon from the lower edge of the last named figure;

Fig. IV is a fragmentary elevation of the rule members, correspoiulingIto Fig. I, 10010 ing in an upward direction from the bottom side thereof;

Fi V is a View similar to Fig. III, but showing the lower rule member displace-d at 90 to the upper one;

Fig; VI is a horizontal section taken transversely thru the middle of Fig. I;

Fig. VII is an underside-plan view of the element depicted in Fi I;

Fig. VIII is a centrallongitudinal section of the same'element; and 1 7 Fig. IX'is a" fragmentary side view, showing adjacent pairs of associated. rule members'held in spaced apart relation tooneanr other. i I I Referringnow to: these several views fora detailed description of the invention thereby exemplified in its preferred embodiment, it will be observedthat the. known parts to which the'sanie is applied-have been desig natedbyletters of reference, instead of nu-. merals as are used for denoting-the present improvement. This was done it will be understood merely to intimate thatthe said parts are not treated or considered as pertaining exclusively to the; latter, but are claimed herein-only in so far asthey form therewithlegitimate combinations of elements 'capable of yiel'din'gnovel and "useful results. I

I Pursuant totheniethed of notation adopt ed, the letterA designates one of apair of superposed or'overlapping, adjacent and graduation-boaring sections or members of an extens on or folding measuring rule, and

B the other or underlying member thereof.

Inconformi'ty with-common practice, the inner or apposed faces of the aforesaid sections are provided with interlocking joint plates C, D, having sets of inter-engaging cam surfaces C1, D1, respectively, adapted as is customary to lit into one another, for maintain in the rule sections aligned, whether in extended or folded condition.

7 In order to accommodateoneset of the before-mentioned cam-portions, C1, the member A with which the same coacts, is routed as indicatedat Al, the companion member B, being onlyrouted centrally thereof, as shown at B1,Fig. II, so as to afford the proper seating for the bottom face of plate D. The means for securing both of these plates to their seats at the ends of the rule members have not been specifically illustrated, as the well known method of driving ears or tongues struck from the bases of the joint plates into the material of which these sections are composed, can be employed. Oppositelydisposed flanges C2, D2, formed with the longitudinal sides of the plates'C, D, respectively, are, as usually is the case, bent so as to clasp around the bevelled, s l vise narrowed edges of the rule sections A, B, near the end portions thereof, for the purpose of tieing the afore- 'namcd part into a firm, assemblage.

From the anionic of the said plates and preierablyint.

portioned to have a working fit, one within the other, to givean adequate bearing intermediately of the plates in question and the theretoattached members of the rule.-

A2, is represented-that one of-these rule sections 1s provided with a thru bore where- 111 is received the outer and larger bearing ferrule C3. It w1llbe understood, as the rule members are being-moved, that is, *swung from one position to the other, anl he cam surfaces C1, D1, incidentally forced apart, arotative as well as an axial'displacement wil-ltake place between the ferrules Cii, D3.

The companion rule member B is furnished "wlth a bore B2, disposed in axial alignment With the bearmg ferrules and designed together with the latter to receive therethru' a 'pintle' E which for the sake of convenience may consist of a hollow rivet. Thus it will. be seen that this pintle'or tubular hinge pin stands in. concentric relationto "the said ferrules. The opposite terminals of pintle "E are headed or rivette'd over as denoted I therewith, extend up ferrules 33,173, in the same direction and proits atEl, the'heads or flanges thus formed being lodged within. shallow pockets, encompassed by hollow, perforate-bosses 11. offset from the rear faccsof elen'ients or flexible plates as shown, the last mentioned recess is made of a depth slightly in excess of the height of the boss-portion of the thereto appertaining element 13 so that the underside 15 of the said boss cannot bottom in the recess B4.

The aforenamed elements or flexible plates 13 are substantially alike and of oblong or elongate formatiombeing preferably stamped of some springy or semi-resilient sheet metal to provide flexibility. From Figs. 1 and VI, it will be observed that the elements or plates 13 in question are disposed cross-wise of the rule members, e. g. transversely relatively to the joint plates thereof. It will also be no ticed with respect to the sectioned views of the drawing hereto annexed, that the size of the bore A2 in one member is approximately the same as the recess Bet in the other member of the rule. From what has just above been stated, it will be comprehended, that exteriorly, the bosses 11 are of a diameter equal to the larger ferrule C3. The advantages of the foregoing details of construction are that the number of tools and operations necessary to perform on the different parts of therule, are reduced to a minimum.

The intermediate portions 17 of the yokeelements 13, namely those situated between the outer ends of the latter and the central bosses 11 thereof, are bowed upwardly or arched to some extent, in order to increase their flexibility. At such times as the rule members are spread apart one away from the other, by virtue of a swinging motion having been imparted to them by a person extending or folding the rule, the aforesaid portions 17 become momentarily flattened to a certain degree, due to the outward force exerted thereon by the members A, B. But immediately the cams C1, D1, thereof have snapped into engagement, the springiness of the said portions of the elements 13 serve to draw and resiliently clamp the rule sections or members firmly but releasably together. yieldable arm portions 17 are bent right angularly thereto on the same side of the elements as their bosses 11, said bent over lips being indicated at 19. The protuberances thus formed are pressed into the hard wood strips of which the rule members are ordinarily made. These lips anchor the yokeelements in their assignedpositions on the rule members and prevent the latter from splitting, especially where they have been reduced or weakened by the bores and recesses intersecting the same. When metal strips are employed instead of wooden ones, it is obvious that rule members of this kind would have to be indented or provided with appropriate cavities to receive the before named lips. The pressure exerted by the clamp elements onto the members of the rule is to greatest extent applied by the outer ends of the former,

Not only do the yoke or clamping elements The opposite free extremities of the,

act to relieve the rule members themselves of the combined bending and twisting stresses usually imposed thereon, but these elements also function, by reason of the fact that they project slightly beyond the outer faces of the members, to guard against the graduations and numbers imprinted on them from coming into rubbing contact, thus prolonging the useful life of a measuring instrument constructed according to the present invention, to many times that ofthe prevailing types of folding rules, and without increasing the manufacturing cost, or sacrificing the strength'and other advantages embodied in this improved article.

Notwithstanding a pair of clamping elements have been shown anddescribed, as ooacting with the opposite outerfaces of adjacent rule members, it is conceivable that under certain conditions, only one of these elements needs to be used, as the flexure required to draw the members together after having been spread apart, can be borne by a single elemen I While a certain preferred embodiment of this joint has been shown and described, it will be understood that changes in the form, arrangements,proportions, sizes and details thereof may be made, without departing from the scope of the invention as defined by the appended claims.

Having described my invention what I desire to secure by Letters Patent and claim,

1. In a folding rule, the combination with the members and the oint plates thereof, of a hinge pintle passing thru said members and plates, and an element having pivotal engagement with an end of said pintle and projecting beyond the outer face of one of the members, said element being bowed crosswise of the rule members-and adapted to" .fiex when the same are swung from one position to another, the flexing of the element avoiding stresses in the said members.

2. In a folding rule, the combination with the members and the joint plates therebetween, of a pivot passing thru said members and plates, and elements widthwise superlying the outer faces of the members and anchored against displacement relatively thereto, the extremities of said elements yieldably engaging the said members, the elements being hin 'edly engaged by said pivot.

3. In a folding rule, the combination with the members and the oint plates for locking the same, of a. pivot passing thru said plates and the thereto attached members, elongate elements yieldingly superposed upon the exterior faces of said members crosswise thereof, said elements beinganchored to said faces and having depressed central recesses there- 1n, the ends of said plvot being headed and operatively received within said recesses, there being ahinged engagement between the latter and the pivot heads, thereby enabling one rule member to be swung relatively to the other.

4. In a folding rule, the combination with the members and the joint plates for retaining' the same in either extended or folded condition, of a pintle passing thru said members and plates, elementsreaching across the exterior faces of the members and provided with hollow bosses recessed therein, the interior of said bosses being adapted to receive headed extremities on said pintle, the latter having pivotal connections with said bosses, and means for fixedly anchoring the outer portions of said elements adjacent the edges of the said members. 7

5. Ina folding rule, the combination With the niembe'rstand the joint plates therebetween, interfitting bearing ferrules formed with said plates, one of said members being bored to accommodate the ferrules, of a pintle passing thru the members and said ferrules, yoke-like spring-elements projecting transversely above the members exterior faces and provided with depressed hollow bosses one whereof is received in said bore, and heads at the ends of said pintle lodged within the hollow of said bosses, said heads affording the pintle rotative movement relative to said elements while serving to tension the yoke port-ions of the latter.

6. In a folding'rnle, the combination with the members and the oint plates-thereof, of a pintle passing therethru, elements overlying the exterior faces of said members transversely, and means anchoring the extremities of said elements in proximity to the edges of the members, the ends of said pintle having pivotal connections with central portions of the elements, the latter projecting above the members and contacting with one another when the said members are in folded condition.

HERMAN M. GASSTROM. 

